1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.htmlviewer; 18 19 import android.app.Activity; 20 import android.content.ActivityNotFoundException; 21 import android.content.ContentResolver; 22 import android.content.Intent; 23 import android.content.pm.PackageManager; 24 import android.Manifest; 25 import android.net.Uri; 26 import android.os.Bundle; 27 import android.provider.Browser; 28 import android.util.Log; 29 import android.view.View; 30 import android.webkit.WebChromeClient; 31 import android.webkit.WebResourceRequest; 32 import android.webkit.WebResourceResponse; 33 import android.webkit.WebSettings; 34 import android.webkit.WebView; 35 import android.webkit.WebViewClient; 36 import android.widget.Toast; 37 38 import java.io.IOException; 39 import java.io.InputStream; 40 import java.net.URISyntaxException; 41 import java.util.zip.GZIPInputStream; 42 43 /** 44 * Simple activity that shows the requested HTML page. This utility is 45 * purposefully very limited in what it supports, including no network or 46 * JavaScript. 47 */ 48 public class HTMLViewerActivity extends Activity { 49 private static final String TAG = "HTMLViewer"; 50 51 private WebView mWebView; 52 private View mLoading; 53 private Intent mIntent; 54 55 @Override 56 protected void onCreate(Bundle savedInstanceState) { 57 super.onCreate(savedInstanceState); 58 59 setContentView(R.layout.main); 60 61 mWebView = (WebView) findViewById(R.id.webview); 62 mLoading = findViewById(R.id.loading); 63 64 mWebView.setWebChromeClient(new ChromeClient()); 65 mWebView.setWebViewClient(new ViewClient()); 66 67 WebSettings s = mWebView.getSettings(); 68 s.setUseWideViewPort(true); 69 s.setSupportZoom(true); 70 s.setBuiltInZoomControls(true); 71 s.setDisplayZoomControls(false); 72 s.setSavePassword(false); 73 s.setSaveFormData(false); 74 s.setBlockNetworkLoads(true); 75 76 // Javascript is purposely disabled, so that nothing can be 77 // automatically run. 78 s.setJavaScriptEnabled(false); 79 s.setDefaultTextEncodingName("utf-8"); 80 81 mIntent = getIntent(); 82 requestPermissionAndLoad(); 83 } 84 85 private void loadUrl() { 86 if (mIntent.hasExtra(Intent.EXTRA_TITLE)) { 87 setTitle(mIntent.getStringExtra(Intent.EXTRA_TITLE)); 88 } 89 mWebView.loadUrl(String.valueOf(mIntent.getData())); 90 } 91 92 private void requestPermissionAndLoad() { 93 Uri destination = mIntent.getData(); 94 if (destination != null) { 95 // Is this a local file? 96 if ("file".equals(destination.getScheme()) 97 && PackageManager.PERMISSION_DENIED == 98 checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)) { 99 requestPermissions(new String[] {Manifest.permission.READ_EXTERNAL_STORAGE}, 0); 100 } else { 101 loadUrl(); 102 } 103 } 104 } 105 106 @Override 107 public void onRequestPermissionsResult(int requestCode, 108 String permissions[], int[] grantResults) { 109 // We only ever request 1 permission, so these arguments should always have the same form. 110 assert permissions.length == 1; 111 assert Manifest.permission.READ_EXTERNAL_STORAGE.equals(permissions[0]); 112 113 if (grantResults.length == 1 && PackageManager.PERMISSION_GRANTED == grantResults[0]) { 114 // Try again now that we have the permission. 115 loadUrl(); 116 } else { 117 Toast.makeText(HTMLViewerActivity.this, 118 R.string.turn_on_storage_permission, Toast.LENGTH_SHORT).show(); 119 finish(); 120 } 121 } 122 123 @Override 124 protected void onDestroy() { 125 super.onDestroy(); 126 mWebView.destroy(); 127 } 128 129 private class ChromeClient extends WebChromeClient { 130 @Override 131 public void onReceivedTitle(WebView view, String title) { 132 if (!getIntent().hasExtra(Intent.EXTRA_TITLE)) { 133 HTMLViewerActivity.this.setTitle(title); 134 } 135 } 136 } 137 138 private class ViewClient extends WebViewClient { 139 @Override 140 public void onPageFinished(WebView view, String url) { 141 mLoading.setVisibility(View.GONE); 142 } 143 144 @Override 145 public boolean shouldOverrideUrlLoading(WebView view, String url) { 146 Intent intent; 147 // Perform generic parsing of the URI to turn it into an Intent. 148 try { 149 intent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME); 150 } catch (URISyntaxException ex) { 151 Log.w(TAG, "Bad URI " + url + ": " + ex.getMessage()); 152 Toast.makeText(HTMLViewerActivity.this, 153 R.string.cannot_open_link, Toast.LENGTH_SHORT).show(); 154 return true; 155 } 156 // Sanitize the Intent, ensuring web pages can not bypass browser 157 // security (only access to BROWSABLE activities). 158 intent.addCategory(Intent.CATEGORY_BROWSABLE); 159 intent.setComponent(null); 160 Intent selector = intent.getSelector(); 161 if (selector != null) { 162 selector.addCategory(Intent.CATEGORY_BROWSABLE); 163 selector.setComponent(null); 164 } 165 // Pass the package name as application ID so that the intent from the 166 // same application can be opened in the same tab. 167 intent.putExtra(Browser.EXTRA_APPLICATION_ID, 168 view.getContext().getPackageName()); 169 170 try { 171 view.getContext().startActivity(intent); 172 } catch (ActivityNotFoundException ex) { 173 Log.w(TAG, "No application can handle " + url); 174 Toast.makeText(HTMLViewerActivity.this, 175 R.string.cannot_open_link, Toast.LENGTH_SHORT).show(); 176 } 177 return true; 178 } 179 180 @Override 181 public WebResourceResponse shouldInterceptRequest(WebView view, 182 WebResourceRequest request) { 183 final Uri uri = request.getUrl(); 184 if (ContentResolver.SCHEME_FILE.equals(uri.getScheme()) 185 && uri.getPath().endsWith(".gz")) { 186 Log.d(TAG, "Trying to decompress " + uri + " on the fly"); 187 try { 188 final InputStream in = new GZIPInputStream( 189 getContentResolver().openInputStream(uri)); 190 final WebResourceResponse resp = new WebResourceResponse( 191 getIntent().getType(), "utf-8", in); 192 resp.setStatusCodeAndReasonPhrase(200, "OK"); 193 return resp; 194 } catch (IOException e) { 195 Log.w(TAG, "Failed to decompress; falling back", e); 196 } 197 } 198 return null; 199 } 200 } 201 } 202